fn test(name: String) {
    println!("name={}", name);
}

fn add(i: i32, j: u64) -> i64 {
    return (i as i64) + (j as i64);
}

fn main() {
    let mut i = 123;
    println!("int的值为: {}", i);

    i = 12;
    println!("int的值为: {}", i);

    let j: u64 = 12222222;
    println!("long的值为: {}", j);

    println!("i + j = {}", add(i, j));

    let k = 123.4;
    println!("int的值为: {}", k);

    let name = String::from("123");
    test(name);

    let a = "123";
    let b = a;
    println!("a={},b={}", a, b);

    println!("hello");
}
